Datasheet

3
LTC1702
1702fa
ELECTRICAL CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: PV
CC
and BV
CC
(V
BOOST
– V
SW
) must be greater than V
GS(ON)
of
the external MOSFETs used to ensure proper operation.
Note 3: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 4: Supply current in normal operation is dominated by the current
needed to charge and discharge the external MOSFET gates. This current
will vary with supply voltage and the external MOSFETs used.
Note 5: Supply current in shutdown is dominated by external MOSFET
leakage and may be significantly higher than the quiescent current drawn
by the LTC1702, especially at elevated temperature.
Note 6: This parameter is guaranteed by correlation and is not tested
directly.
Note 7: Rise and fall times are measured using 10% and 90% levels. Delay
and nonoverlap times are measured using 50% levels.
The denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
CC
= 5V unless otherwise specified. (Note 3)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Switching Characteristics
f
OSC
Oscillator Frequency Test Circuit 1, C
L
= 0pF 475 550 750 kHz
Φ
OSC2
Converter 2 Oscillator Phase Relative to Converter 1 (Note 6) 180 DEG
DC
MIN1
Minimum Duty Cycle V
FB
< V
MAX
710 %
DC
MIN2
Minimum Duty Cycle V
FB
> V
MAX
0%
DC
MAX
Maximum Duty Cycle 87 90 93 %
t
NOV
Driver Nonoverlap Test Circuit 1, C
L
= 2000pF (Note 7) 40 100 ns
t
r
, t
f
Driver Rise/Fall Time Test Circuit 1, C
L
= 2000pF (Note 7) 12 80 ns
Feedback Amplifier
A
VFB
FB DC Gain 74 85 dB
GBW FB Gain Bandwidth 25 MHz
I
ERR
FB Sink/Source Current ±3 ±10 mA
V
MIN
MIN Comparator Threshold 760 785 mV
V
MAX
MAX Comparator Threshold 815 840 mV
Current Limit Loop
A
VILIM
I
LIM
Gain 40 dB
I
IMAX
I
MAX
Source Current I
MAX
= 0V, LTC1702C –7 10 13 µA
I
MAX
= 0V, LTC1702I –7 10 14 µA
Status Outputs
V
PGOOD
PGOOD Trip Point V
FB
Relative to Regulated V
OUT
–10 5 –2 %
V
OLPG
PGOOD Output Low Voltage PGOOD = 1mA 0.03 0.1 V
I
PGOOD
PGOOD Output Leakage ±0.1 ±1 µA
t
PGOOD
PGOOD Delay Time V
FB
< V
PGOOD
to PGOOD (Note 7) 100 µs
V
FAULT
FAULT Trip Point V
FB
Relative to Regulated V
OUT
+10 +15 +20 %
V
OLF
FAULT Output Low Voltage I
FAULT
= 1mA 0.03 0.1 V
I
FAULT
FAULT Output Current V
FAULT
= 0V 10 µA
t
FAULT
FAULT Delay Time V
FB
> V
FAULT
to FAULT (Note 7) 25 µs